Molecular logic gates: the past, present and future

Four-colour response to self-sorting of mixed monolayer-protected metal nanoparticles

Selective aggregation of gold and silver nanoparticles in water, leading to distinctly coloured states, can be achieved using particles with suitable ligands and bis(cyclodextrins) as the linking units.

CRISPR/Cas Multiplexed Biosensing: Advances, Challenges, and Perspectives

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) protein systems are renowned for their high sensitivity and specificity, enabling them as a powerful diagnostic toolbox. Multiplexed detection of panels of targets, as opposed to single targets, is imperative for reliable and conclusive disease diagnostics. However, multiplex application of the CRISPR/Cas system has long been hindered by indistinguishable signals from specific targets due to nonspecific chaotic trans-cleavage. To make a breakthrough, substantial efforts have been devoted to CRISPR/Cas-powered multiplexed biosensing strategies, which consequently experienced rapid development over the past five years. This review systematically summarizes recent advances in CRISPR/Cas multiplexed detection encompassing Cas9, Cas12, and Cas13. Key focus issues include multiplex biosensing strategies and their respective advantages and limitations, sensing mechanisms, and detection performance of novel validated examples. Finally, the status and challenges of CRISPR/Cas multiplexed biosensing are critically discussed, and future outlooks are proposed for their potential practical application. This Perspective aims to inspire significant research and promote the development of the next generation of CRISPR/Cas multiplexed biosensing.

DNA Logic-Integrated Quantum Nanosensor for MicroRNA Diagnostics

Nanodiamonds (NDs) with nitrogen-vacancy (NV) centers are emerging as powerful quantum nanosensors (QNs) in biomedical applications due to their exceptional sensitivity. However, achieving optimal diagnostics performance necessitates both high sensitivity and selectivity; especially in practical biomedical settings, it remains challenging for QNs to provide quantitative analyses when multiple analytes are present. Here, we present a biosensing platform that integrates DNA logic gates (DLGs) with spin-based quantum sensing, termed DLG-QN for ultrasensitive and ultraselective diagnostics. Utilizing an AND DLG, both NDs and magnetic beads (MBs) are functionalized with hairpin DNA strands. In the presence of both miRNA-21 and miRNA-155key biomarkers overexpressed in cancerthe hairpin DNAs undergo conformational changes that facilitate DNA-guided self-assembly of NDs and MBs, enriching the target signal. Resonant microwave modulation of ND fluorescence emission allows for high signal-to-noise ratio (SNR) detection by separating the signal from background fluorescence via spin-enhanced analysis. This platform demonstrated ultrasensitive and ultraselective detection of miRNA-21 and miRNA-155 with a limit of detection of 19.8 fM, highlighting its potential as a general biosensing strategy for precision diagnostics involving multiple biomarkers.

An ESIPT-Based Fluorochromogenic Tweezer for Reversible and Portable Detection of Al3+ Ions

ESIPT-based fluorochromes are promising materials for the detection of various chemical and biological species, particularly metal cations. Herein, we have meticulously designed a prototypical ESIPT-based α-naphtholphthalein-derived "turn-on" fluorogenic tweezer, NPDM, for the selective detection and visualization of Al3⁺ in biological and environmental samples. NPDM was found to specifically interact with Al3⁺, exhibiting dual emissions, high sensitivity (50 s), large Stokes shifts (140 and 176 nm), and a low detection limit of 16.3 nM. Notably, the sensing mechanism of NPDM for Al3⁺ involves metal ion-coordination-induced fluorescence enhancement (CHEF), ESIPT "turn-on" effect as well as restricted intramolecular rotation (RIR). This mechanism is supported by Job's plot, high-resolution mass spectrometry (HRMS), proton nuclear magnetic resonance (¹H NMR) titrations, and density functional (DFT) calculations. Interestingly, the NPDM-Al3+ ensemble can function as a secondary chromo-fluorogenic tweezer for monitoring fluoride ions (F-) with a low detection limit of 34.8 nM. Thus, an advanced molecular memory device was constructed based on the fluorescence "off-on-off" strategy and its excellent sensing properties. Moreover, a portable, smartphone-assisted intelligent platform has been developed to facilitate in-field, cost-effective, and accurate detection of Al3⁺ in real environmental water samples. Significantly, NPDM was successfully employed to image intracellular Al3⁺ and F⁻ ions in HeLa cells without interference from oxidative stress. This represents the first reported smart molecular tweezer capable of detecting Al3⁺ ions generated during electroporation within living cells. Furthermore, the strategy developed here is valuable for the creation of novel, practically beneficial luminescent molecules and offers an advanced luminescent detection platform for point-of-care sensing of health-related ionic species.

Collective Bistability of Pyridine-Furan Nanosprings Coupled by a Graphene Plate

Nanometer-sized molecular structures exhibiting mechanical-like switching between discrete states are of great interest for their potential uses in nanotechnology and materials science. Designing such structures and understanding how they can be combined to operate synchronously is a key to creating nanoscale functional units. Notable examples recently discovered using atomistic simulations are pyridine-furan and pyridine-pyrrole nanosprings. When slightly stretched in aqueous or organic solutions, these nanosprings exhibit bistable dynamics akin to Duffing nonlinear oscillators. Based on these findings, we designed a hybrid system consisting of several pyridine-furan nanosprings attached to a graphene plate in organic solvent and simulated the molecular dynamics of the construct. Our focus is on how the nanosprings coupled by a graphene plate work together, and whether such a design enables the nanosprings to respond synchronously to random perturbations and weak external stimuli. Molecular dynamics simulations of this specific construct are complemented by a theoretical model of coupled bistable systems to understand how the synchronization depends on coupling of bistable units.

Using Color to Control Conformation in a Chemical System Containing Multiple Tricyanofuran Photoacids

Color vision relies on selective, reversible isomerization by visible light of a mixture of retinyl chromophores in photoreceptor cells. Synthetic molecular mimics of this wavelength-dependent induction of function are rare, despite the attractiveness of controlling chemical processes solely by the wavelength of incident light. Here, we report a color-responsive chemical system that is composed of a cationic receptor complex, two competing chiral anionic ligands, and two metastable photoacids with contrasting absorption properties. Tricyanofuran photoacids are synthesized with absorption maxima of varying wavelengths across the whole visible spectrum. Protons released by the photoacids upon selective irradiation reversibly mask the more basic receptor-bound ligand, leading to ligand exchange that can be observed as a shift in the circular dichroism (CD) spectrum of the reporter complex. A ≈90 nm separation between the absorbance maxima of the photoacids allowed each to be selectively photoisomerized in the presence of the other. The concentration of released protons, and hence the magnitude of the shift in CD response, are controlled by changing the wavelength of the incident visible light. Different output behaviors (OR/AND logic gates and wavelength detection) are programmed into the system by varying the relative proportions of the photoacids.

Multi-State Redox and Light-Driven Switching of Pseudorotaxanation and Cation Shuttling

The modulation of molecular recognition underpins numerous wide-ranging applications and has inspired the development of a myriad of switchable receptors, in particular photo- or redox-responsive hosts. Herein, we report a highly versatile three-state cation receptor family and switch system based on an overcrowded alkene strapped with crown ethers, which can be switched by both redox and light stimuli, thereby combining the advantages of both approaches. Specifically, the neutral switches can be quantitatively converted between anti- and syn-folded receptor geometries by irradiation, leading to the discovery of a significant increase or decrease in cation binding affinity, which was exploited to shuttle the pseudorotaxane-forming dibenzylammonium guest between the switchable crown ethers of slightly different sizes. Alternatively, two-electron oxidation to the orthogonal, dicationic, nonvolatile state completely turns off cation binding to the host, thereby ejecting the guest. Upon reduction, the metastable syn-folded state is first formed, which then thermally relaxes, resulting in a unique, autonomous, and cation-dependent multistate switching cascade.

Reconfigurable logic operations for fluorescent sensing of drug resistant and/or hypoxic cancer cells

Precision diagnosis is of great importance and can be achievable through information processing sensors. A distyryl pyridinium BODIPY decorated with nitroreductase and esterase enzyme responsive modules is shown to display configurable fluorescence read out upon enzyme-catalysed elimination reaction creating pyridine distyryl BODIPYs. Discrimination of the cellular profile, i.e. drug resistance and hypoxic microenvironment, is achieved with a single molecule through reconfigurable molecular logic gate operations.

Algorithm in chemistry: molecular logic gate-based data protection

Data security is crucial for safeguarding the integrity, authenticity, and confidentiality of documents, currency, merchant labels, and other paper-based assets, which sequentially has a profound impact on personal privacy and even national security. High-security-level logic data protection paradigms are typically limited to software (digital circuits) and rarely applied to physical devices using stimuli-responsive materials (SRMs). The main reason is that most SRMs lack programmable and controllable switching behaviors. Traditional SRMs usually produce static, singular, and highly predictable signals in response to stimuli, restricting them to simple "BUFFER" or "INVERT" logic operations with a low security level. However, recent advancements in SRMs have collectively enabled dynamic, multidimensional, and less predictable output signals under external stimuli. This breakthrough paves the way for sophisticated encryption and anti-counterfeiting hardware based on SRMs with complicated logic operations and algorithms. This review focuses on SRM-based data protection, emphasizing the integration of intricate logic and algorithms in SRM-constructed hardware, rather than chemical or material structural evolutions. It also discusses current challenges and explores the future directions of the field-such as combining SRMs with artificial intelligence (AI). This review fills a gap in the existing literature and represents a pioneering step into the uncharted territory of SRM-based encryption and anti-counterfeiting technologies.

An information processing triple input fluorescent probe for melanoma cancer

BACKGROUND

Multi-analyte responsive fluorescent sensors are promising tools for selective imaging of malignant tissues. Glutathione tripeptide is a common cancer biomarker. Tyrosinase enzyme is involved in melanogenesis and neuroactive dopamine synthesis. Activity/level of this enzyme is significantly altered in various diseases including melanoma and neurological diseases. Molecular tools capable of sensing different cellular states are yet to be developed. In the research presented here, a novel reconfigurable pyridinium functionalized distyryl-BODIPY P2 is developed as tyrosinase sensor with the synergistic effect of glutathione and carboxylesterase to discriminate different pathological cellular states.

RESULTS

Acetyl-masked tyrosinase responsive 3-hydroxybenzyl substrate analogue is attached to the sensor. Following the ester hydrolysis by carboxylesterase, tyrosinase mediated oxidation to catechol followed by spontaneous 1,6-elimination generates pyridine BODIPY P1, resulting in 81 nm hypsochromic shift in aqueous solution compared to parent probe P2. Glutathione further enhances the response by removing acetyl group and/or reducing the quinone by-product back to cleavable quinol. A molecular AND logic gate can be constructed with enzymes and GSH, enabling multi-analyte melanoma sensing. Setting the fluorescence output threshold, distinct phenotypes can be diagnosed i.e. drug-resistant melanoma. Tyrosinase expressing B16-F10 melanoma cells display a significantly increased fluorescence when incubated with P2 compared to breast cancer cells. When inhibitor of any of the inputs is used, fluorescence intensity is significantly reduced, proving the synergistic effect of all disease parameters.

SIGNIFICANCE

With versatile chemistry and sufficient solubility in aqueous media, this structure provides the first triple input Near-IR fluorescent sensor for melanoma with the potential of discriminating different pathological status. Modular structure can provide a common scaffold for information processing molecular sensors for hydrolytic/oxidoreductive enzymes and/or disease associated analytes.

Integrating CRISPR-Cas12a with Aptamer as a Logic Gate Biosensing Platform for the Detection of CD33 and CD123

Molecular logic gates, as biomolecule-based computational systems, are highly suitable for multitarget detection due to their programmability and modularity. However, existing systems are primarily limited to nucleic acid detection and have not been widely applied to disease-related sensing, particularly for disease antigens. CD33 and CD123 are critical biomarkers for acute myeloid leukemia (AML), yet conventional detection methods rely on expensive equipment and complex procedures, limiting their accessibility and practicality. This study designs a DNA logic gate system integrating nucleic acid aptamers, catalytic hairpin assembly (CHA), and CRISPR-Cas12a, pioneering its use for AML antigen detection. The system comprises three modules: input recognition, signal amplification, and signal transduction. Nucleic acid aptamers specifically identify CD33 and CD123, while CHA enables efficient signal amplification and CRISPR-Cas12a generates a fluorescent output via trans-cleavage activity. The system operates stably at room temperature and implements multiple logic gate models, including YES, OR, AND, NOR, and INHIBIT, enabling the simultaneous detection of CD33 and CD123. Experimental results are visually distinguishable under blue light, and the system requires only standard fluorescence detection instruments. In serum samples, it exhibits excellent selectivity and stability, with a detection limit of 0.5 ng/mL. This study pioneers the application of logic gate technology for disease antigen detection, addressing a critical gap in AML biomarker sensing. Our study indicates that this logic detection platform, characterized by its simplicity in operation, high sensitivity, and versatility in logic functions, holds promise as a potent sensing system for the intelligent multiplex target detection of disease antigens, environmental pollutants, and heavy metals.

De novo design of dual-detection fluorescent sensors for bisulfite and copper (II) ion based on cascade activation

BACKGROUND

Cascade activated probes have received extensive attention due to their sequence-dependent detection of multiple markers in pathologic pathways. HSO3- and Cu2+ are biomarkers of intracellular mitochondrial activity, and their simultaneous detection is of great significance. Until now, probes that detect them simultaneously were all based on displacement mechanism with "ON-OFF-ON" switches in an emission channel. In other words, using HSO3- and Cu2+ as two inputs in logic sensing, the inputs of (0,0), (0,1), or (1,1) gave the same "1" output. Therefore, they suffered from the false positive signals in clinical application.

RESULTS

The de novo design of fluorescent probes with a more advanced sensing mechanism was explored. The four dyes, CM-Cu, CMA-Cu, R1, and R2, have similar structures, but their sensing behaviors are quite different. For dual detection of HSO3- and Cu2+, CM-Cu showed emission "ON-OFF-ON" switches based on IMP logic gate; while CMA-Cu, having one more aldehyde, was cascade activated based on AND gate for the first time. Noteworthily, unlike most dual-locked probes, which usually involve a complex synthesis process, here, cascade activation by HSO3- and Cu2+ is achieved by adjusting the electron distribution of a ready-made structure. Coupled with its low toxicity, high specificity, strong solid emission, and anti-diffusion ability, the sensing property of CMA-Cu have been validated in digital encryption and cell imaging.

SIGNIFICANCE

We exhibited how to adjust the dual recognition from displacement to cascade activation by fine-tuning the molecular structure. This study may provide a new idea for the simple design of dual-locked probe, which is helpful for the sequential detection of multiple biomarkers with physiological correlation and could improve the accuracy of disease diagnosis.

Cinchona alkaloid copolymers as fluorimetric INHIBIT and colorimetric AND logic gates for detection of iodide

Four cinchona alkaloid-acrylamide water soluble copolymers with a mean hydrodynamic diameter of 3 nm were synthesised by free radical polymerization. The copolymers were characterised by 1H NMR, FTIR, GPC, DLS, UV-vis and fluorescence spectroscopy. A blue emission is observed with H+ switching of 185 and 175-fold for the quinidine and quinine copolymers, and 21 and 11-fold for the cinchonine and cinchonidine copolymers, while the presence of Cl-, Br- or I- causes fluorescence quenching. In emission mode, the copolymers function as fluorescent H+, X--driven INHIBIT logic gates (where X = Cl-, Br- or I-). In absorbance mode, the copolymers function as colorimetric H+, I--driven AND logic gates in 1 : 1 (v/v) THF/water with a 76-fold enhancement. The solution colour changes from colourless to yellow with formation of new absorbance bands at 288 nm and 353 nm due to a π-anion non-covalent charge transfer interaction. The copolymers may be useful as selective iodide sensors for medical and analytical diagnostics.

Scaling-up molecular logic to meso-systems via self-assembly

Due to the small size and biocompatibility of molecules, molecular logic-based computation is a gateway to the informational basis of life processes. Logic-based computation operates widely with discrete molecules of up to nanometric sizes. The contribution of molecule-based bulk materials of milli/centimetric size to the field has begun in more recent years. However, artificial molecule-based meso-scale systems which intrinsically perform logic operations are very rare. Here, we show that self-assembled systems consisting of cyclophane octacarboxylates and a cationic surfactant can perform such functions, where a membrane itself behaves as a Reset-Set Flip-Flop which is integrated with 7 more logic elements. Now that molecular logic-based computation operates across a wide range of contiguous size-scales, the way opens for its general use in information processing aspects of biology and synthetic biology.

Enlightening molecular logic: basics, tools and techniques for newcomers

As silicon-based technologies approach their physical limits, the search for alternative computing paradigms becomes imperative. Molecular logic has emerged as a promising approach, particularly the systems based on trivalent lanthanide ions that exploit the unique photophysical properties of these ions to implement Boolean logic operations. This focus article provides a comprehensive introduction to the principles, methodologies, and recent advancements in luminescence-driven molecular computing. Designed for newcomers, it outlines the fundamental concepts, essential experimental techniques, and standardized protocols for characterizing luminescent molecular logic devices. The advantages of these devices, such as energy efficiency, multiplexing capabilities, and adaptability to complex environments, are also critically examined. Addressing some limitations of traditional electronics, molecular logic paves the way for innovative applications in diagnostics, sensing, and novel computational architectures, offering a transformative and sustainable pathway for next-generation information processing.

Advanced Logic Computing and Hybrid Crypto-Steganography for Molecular Information Coding Using Gold/Silver Nanoclusters

In the domain of digital data exchange, ensuring information security is the supreme demand for data storage and transmission. Interlinking cryptographic techniques with steganographic principles can enhance data confidentiality. However, there have been no reports thus far to develop molecular platforms for hybrid crypto-steganography systems. Using our synthesized nanoclusters (BSA-Au/Ag NCs) through bovine serum albumin (BSA) as a versatile scaffold, we fabricated a molecular platform for concatenated logic circuits and molecular keypad lock. Then, we integrate terrestrial direction information transmission through molecular navigation, employing a double block cipher by combining stego key and shifting cipher key techniques to develop a hybrid crypto-steganography system, aimed at enhancing security paradigms. Furthermore, we prioritize information protection by developing an enhanced distress call protocol using a polyalphabetic cipher to activate covert communication capabilities, thereby safeguarding data against potential infiltrators.

Reversible gating of singlet fission by tuning the role of a charge-transfer state

Stimulus-responsive triplet excited states and multiexcitonic logic gates have garnered increasing interest. Singlet fission is an efficient multiple exciton generation process, in which one singlet converts into two triplets. Singlet fission is, however, rarely reported to be switchable by external stimuli. Here we design a meta-diethynylphenylene-linked tetracene dimer featuring pyridyl endgroups that function as an acid/base-responsive switch, enabling the reversible modulation of singlet fission. In its neutral form, the interchromophore charge-transfer state facilitates singlet fission and promotes the formation of a correlated triplet-pair state. Upon treatment with acid, protonation of the pyridyl nitrogens generates a more strongly electron-accepting pyridinium, leading to an intra-chromophore charge-transfer state, which inhibits singlet fission. Finally, an IMPLICATION logic gate is constructed by using acid and base as inputs and monitoring the formation of triplet excited states based on singlet fission.

Primordial Molecular 1-Bit Magnitude Comparator in Consort with Excitation-Guided Mouldable Logic Systems: A Guided Design of Regular Interactions between Molecules

In addition to designing certain excitation modulated logic systems, we have created the first-ever genuine molecular 1-bit magnitude comparator, using acid and base guided varied absorption responses at separate channels. Designed and manufactured Bifunctional Bis(indolyl)methane Derivative (1) demonstrates distinct optical responses (in UV-visible and fluorescence mode) to a range of chemical stimuli (acid, base, Hg2+, Cu2+, EDTA, GSH, etc.) in aqueous medium. Intriguingly, the compound's excitation-modulated fluorescence responses appeared to change at different detection channels depending on whether the aforementioned analytes were present or not. We have proposed not only an excitation driven logic system with switchable molecular IMPLICATION and XNOR logic gates, but also a molecular 1-bit magnitude comparator in our proposal. A second excitation driven logic system with switchable molecular COMPLEMENT and NOR logic gates was also designed with two different optical channels and used Hg(II) & Cu(II) as chemical inputs.

Sensing with Precision: The R2-Fluorescent Probe as a Smart Tool for Metal Ion Detection

We present the synthesis, characterisation, and application of a novel R2-based fluorescent probe for selective metal ion detection. Comprehensive studies using UV-Vis absorption and photoluminescence spectroscopy revealed strong binding with cobalt (Co2+) and aluminium (Al3+) ions, with a 2:1 binding stoichiometry (probe: metal) and with a detection limit as low as 5.5 × 10-8 mol/L for aluminium and 3.2 × 10-8 mol/L for cobalt, highlighting its remarkable sensitivity. With no interference from other metal ions, the probe showed outstanding stability and selectivity over a broad pH range. Analyses of actual water samples verified its usefulness in environmental monitoring. To further demonstrate the probe's potential in sophisticated sensing applications, it was also used to build a molecular logic gate. The experimental results were theoretically supported by Density Functional Theory (DFT) calculations, which also shed light on the binding mechanism. The R2 probe is emphasised in this work as a sensitive, specific, and adaptable instrument for environmental analysis and metal ion detection.

Rational design of an isatin-based colorimetric and solvatochromic receptor for carbonate ions and its application in molecular-scale logic gates & memory units

A simple and highly sensitive isatin-based colorimetric sensor ISAT 3(a-d) was synthesized through a single-step reaction. The as-prepared receptor ISAT 3b with carbonate ions (CO32- ions) shows a significant red shift in the UV-visible absorption spectra and a visible color change from pale yellow to pink. Also, the receptor ISAT 3b shows unique solvatochromic behavior with CO32- ions in different aprotic solvents and solvent compositions. Moreover, the receptor's pink coloration (absorption maxima at 544 nm) with CO32- ions could be reversible by adding HSO4- ions (attain initial pale-yellow color, absorption maxima at 425 nm), which can be repeatable. The observed color changes with spectral shift and reversibility of the receptor with CO32- ions and HSO4- ions provide "ON-OFF" switching for applying molecular logic gates. Receptors exhibited properties, such as reversibility and repeatability, benefit the design of a molecular-scale sequential memory unit with a display of "Writing-Reading-Erasing-Reading". The real sample analysis was also carried out to prove the practical applicability of receptor (ISAT 3b) for detecting CO32- ions.

Preeminent designing of complementary ternary TRANSFER and COMPLEMENT alongside excitation modulated molecular logic systems

This article describes an optically adjustable, dual complementary ternary molecular TRANSFER and COMPLEMENT logic gate as well as an extremely rare design of excitation-modulated logic systems using a pyrene coupled bis(indolyl)methane derivative (1) in Brij-58 micelles, triggered by different chemical stimuli. We have looked into the optical response of the probe molecule towards variety of analytes, including OH-, CN-, Hg2+, EDTA etc., at various excitation channels, in order to achieve this goal. By utilizing the probe's intriguingly distinct absorption spectra in response to the injection of OH-, Hg2+, and CN- individually or in succession, tunable molecular ternary logic systems were created. In the current report, fundamental and combinational array structures for the ternary logic circuits have been proposed. Furthermore, based on discernible fluorescence responses of the probe molecule towards unlike analytes at various emission wavelengths, a new type of excitation-modulated logic system has been developed.

Lysosome-targeted dual-locked NIR fluorescent probe for visualization of H2S and viscosity in drug-induced liver injury and tumor models

BACKGROUND

Lysosomes, as an indispensable subcellular organelle have numerous physiological functions closely associated with H2S and viscosity, and accurate assessment of H2S/viscosity fluctuations in lysosomes is essential for gaining a comprehensive understanding of lysosome-related physiological activities and pathological processes. The previous single-response fluorescent probes for either H2S or viscosity alone have the potential to generate "false positive" signals in a complex biological environment. In contrast, dual-locked probes can simultaneously respond to multiple targets simultaneously, which could effectively eliminate this defect. Therefore, it is essential to constructed a lysosome-targeted dual-locked NIR fluorescent probe for imaging H2S and viscosity.

RESULTS

In this study, we developed a lysosome-targeted dual-locked NIR fluorescent probe (LFP-N3) for imaging H2S and viscosity based on an integrated ICT-TICT process. In the presence of both H2S and high viscosity conditions, the azide moiety of LFP-N3 reacts with H2S, resulting in the formation of LFP-NH2 that facilitates the ICT process; high viscosity condition further restricts the chemical bond rotation of LFP-NH2, which suppresses the TICT process. As a result, the fluorescence signal of LFP-N3 is significantly enhanced at 690 nm with a large Stokes shift (190 nm). Cytotoxicity assay and colocalization experiments in living cells indicated LFP-N3 possessed low cytotoxicity and precise lysosome-targeted capability. Moreover, both in vitro and in vivo experiments further validated that the fluorescence signal of LFP-N3 can be triggered by the presence of both H2S and high viscosity in tumor and drug-induced liver injury models.

SIGNIFICANCE

The lysosome-targeted dual-locked NIR fluorescent probe has been successfully utilized to imaging H2S and viscosity in vitro and in vivo. Compared with the single-response fluorescent probes, the dual-locked NIR probe (LFP-N3) could effectively mitigate false-positive signals and increase spatial resolution, and has great potential to be developed as a novel diagnostic agent for lysosome-related diseases.

Utilizing sulfa drugs' pH-dependent spectral modifications for designing molecular logic gates

In this study, the absorption and fluorescence characteristics of sulfa drugs, specifically Sulfadiazine (SDZ), Sulfamerazine (SMZ), and Sulfamethazine (STZ), were examined across a pH range of 1-14. The absorption and fluorescence spectra of these sulfa drugs showed significant changes depending on the pH value. Analysis of their pH-dependent absorption and fluorescence properties indicated that these sulfa drugs could used to design molecular logic gates. The absorption and fluorescence behaviors at various wavelength maxima were utilized to design IMPLICATION and Improved-INHIBIT (I-INHIBIT) molecular logic gates.

Pseudohelicene chemosensor displaying ternary signaling stimulated by hydrostatic pressure and solvent

Herein, we report the serendipitous discovery of a racemic chemosensor ([2]HA2) that outputs three signal patterns (1/0/-1) in response to two external stimuli (hydrostatic pressure and solvent); these signals can be observed by hydrostatic pressure spectroscopy.

A Molecular Logic Gate Enables Unconventional Super-resolution Same-Day Imaging of Lysosome Membrane in Live Cells

Lysosomes are acidic membrane-bound organelles that aid digestion, excretion, and cell renewal. The lysosomal membranes are essential for maintaining lysosomal functions and cellular homeostasis. In this work, we developed a molecular "NOR" logic gate, SIATFluor-580L, by introducing malachite green into the spirocyclic rhodamine. SIATFluor-580L requires restriction of molecular rotation of the malachite green motif (Input 1, tight membrane structure) and a large amount of H+ ions to convert the spirocyclic rhodamine into the zwitterionic form (Input 2, acidic environment) to produce a fluorescent product (Output), providing a fluorogenic probe to visualize the lysosomal membrane dynamics in living cells with subdiffraction resolution by using HyVolution (also known as Lightning), an unconventional and inexpensive super-resolution imaging approach based on a basic confocal optical system.

Salicylidene-based dual-responsive 'turn on' fluorometric chemosensors for the selective detection of Zn2+, Al3+ and F- ions: theoretical investigation and applications in the live cell imaging of zebrafish larvae and molecular logic gate operation

Four salicylidene-based dual-responsive chemosensors 1,5-bis(5-bromosalicylaldehyde)carbohydrazone (R1), 1,5-bis(5-bromosalicylaldehyde)thiocarbohydrazone (R2), 1,5-bis(3-ethoxysalicylaldehyde)carbohydrazone (R3) and 1,5-bis(3-ethoxysalicylaldehyde)thiocarbohydrazone (R4) were synthesized and characterized. The molecular structures of R1 and R3 were confirmed by single crystal X-ray diffraction technique, which crystallized in the orthorhombic Pbcn and monoclinic P21/n space groups, respectively. The chemosensor molecules were investigated for their recognition properties against the selected cations (K+, Ca2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Fe3+ and Al3+) and anions (F-, Cl-, Br-, I-, HSO4-, H2PO4-, ClO4-, N3- and NO3-) by colorimetry, absorption spectroscopy, fluorescence spectroscopy, 1H NMR spectroscopy and theoretical studies. The sensor molecules showed colorimetric responses for the Co2+, Ni2+, Cu2+ and Fe3+ cations and the F- anion. Interestingly, the Zn2+ and Al3+ cations showed only the 'turn on' fluorometric response, whereas the F- anion showed both colorimetric and fluorometric responses. The binding constants were determined using the Benesi-Hildebrand (B-H) equation from the fluorescence titrations and found to be higher for R3 towards the Al3+ cation (2.03 × 106 M-1) with a low limit of detection (1.79 μM) and for R4 towards the F- anion (5.13 × 105 M-1) with a low limit of detection (5.23 μM). The chemosensors established 1 : 2 and 1 : 1 binding stoichiometries with the sensed cations and anion, respectively, as confirmed by Job's plots. The computational studies show a lower band gap of HOMO-LUMO when the chemosensors bind with the sensed inorganic ions compared to the free chemosensors. Furthermore, the observed fluorescent behaviour of the Zn2+ and Al3+ cations have motivated us to investigate the practical applications in the live cell-imaging of zebrafish larvae as well as in the development of a molecular logic gate.

Mechanoelectrical Transduction through Anion Recognition with Naphthalenediimide Monolayers at the Air-Water Interface

In biological systems, various stimuli and energies are transduced into membrane potentials via ion transport or binding. The application of this concept to artificial devices may result in biomimetic signal transmitters and energy harvesters. In this study, we investigated the mechanical control of fluoride anion recognition with naphthalenediimide (NDI) monolayers at the air-water interface. Similar to the mechanosensitive ion channels in biological membranes, mechanical stimuli modulated the packing manner of the NDI monolayers, which reproducibly triggered anion binding and concomitant shifts in the membrane potential. Furthermore, mechanical stimuli resulted in anion binding or release, depending on the structure of the alkyl side chains attached to the NDI core, which was explained by the difference in the packing manner of the NDI monolayers. These findings provide insights into the development of novel mechanoelectrical transduction systems that mimic biological processes.

Emergent Behavior of a Photoswitchable Solute in a Biphasic Solvent System

Due to thermal E/Z isomerization, hydrazones in solution typically exist in thermodynamic equilibria between their isomers. Irradiation of such solutions leads to photostationary states that may differ from the equilibrium distribution. Operating such switchable hydrazones in a biphasic system of two immiscible solvents introduces three new degrees of freedom: the E/Z equilibrium in the second solvent and two equilibria for distribution of each of the isomers between the solvents. Irradiation of such a system can be performed in three different ways - the first solvent only, the second solvent only, and both solvents at once - all yielding distinct outcomes. Depending on the choice of materials and the mode of irradiation, such setup may lead to different emergent behaviors that are not immediately intuitive, including net cyclic transport or the accumulation of one photoswitched product in one of the phases, beyond what is reachable by irradiating a simple solution of the same photoswitch.

Networked Multicomponent Ensemble as AND Gate with FRET Output

A networked supramolecular logic AND gate system is accomplished using precise chemical communication within a multicomponent ensemble via metal ion-driven self-sorting processes. The cybernetic AND gate is composed of a copper(I)-loaded nanoswitch, an aza-crown ether and a rhodamine receptor. The modus operandi of the AND gate, from state (0,0), was induced with stoichiometric amounts of two inputs (IN-1=Hg2+, IN-2=Li+) generating copper(I) ions as output only in state (1,1). Generation of state (1,1) from state (0,0) involves selective Cu+ ion translocation from the nanoswitch to the aza-crown ether in the first step (IN-1) and then from the aza-crown ether to the rhodamine receptor in the second step (IN-2). The released copper(I) output acts as a messenger that binds to the rhodamine receptor, triggering it's spiro-lactam ring opening, which leads to a diagnostic FRET emission from the copper(I)-loaded rhodamine scaffold accompanied by a remarkable fluorescence and colour change from pale yellow to pink.

Aza-BODIPY-based logic gate chemosensors and their applications

Dimethylaniline-substituted aza-BODIPY dyes (DA, DM, DP) were designed and synthesized aiming for ion detection. The Zn2+ recognition ability was found in all compounds and the binding mechanism was possibly via dimethylaniline sites linked to the aza-BODIPY core. Upon Zn2+ addition, the new absorption band and the color change occurred due to the altered charge transfer of the adducts. The custom-made colorimeter was successfully integrated into the dye's application, demonstrating a good linear relationship between resistance values and Zn2+ concentration. The chromophore test strips were fabricated and exhibited distinct color changes upon aqueous Zn2+ exposure. The compound DA also exhibits logical behavior with DA-Zn2+-Cu2+ system. In terms of environmental hazards, the compounds exhibited no adverse effect on Pseudomonas putida at the concentration level of 0.2 mg/mL. These findings indicated that all synthesized aza-BODIPYs might be suitable for chemosensor probes for Zn2+ detection with possibly low environmental risk.

Merocyanines: Electronic Structure and Spectroscopy in Solutions, Solid State, and Gas Phase

Merocyanines, owing to their readily tunable electronic structure, are arguably the most versatile functional dyes, with ample opportunities for tailored design via variations of both the donor/acceptor (D/A) end groups and π-conjugated polymethine chain. A plethora of spectral properties, such as strong solvatochromism, high polarizability and hyperpolarizabilities, and sensitizing capacity, motivates extensive studies for their applications in light-converting materials for optoelectronics, nonlinear optics, optical storage, fluorescent probes, etc. Evidently, an understanding of the intrinsic structure-property relationships is a prerequisite for the successful design of functional dyes. For merocyanines, these regularities have been explored for over 70 years, but only in the past three decades have these studies expanded beyond the theory of their color and solvatochromism toward their electronic structure in the ground and excited states. This Review outlines the fundamental principles, essential for comprehension of the variable nature of merocyanines, with the main emphasis on understanding the impact of internal (chemical structure) and external (intermolecular interactions) factors on the electronic symmetry of the D-π-A chromophore. The research on the structure and properties of merocyanines in different media is reviewed in the context of interplay of the three virtual states: nonpolar polyene, ideal polymethine, and zwitterionic polyene.

An "AND" logic gate-based supramolecular therapeutic nanoplatform for combatting drug-resistant non-small cell lung cancer

Despite targeted therapies like epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), non-small cell lung cancer (NSCLC) remains a clinical challenge due to drug resistance hampering their efficacy. Here, we designed an "AND" logic gate-based supramolecular therapeutic platform (HA-BPY-GEF-NPs) for the treatment of EGFR-TKI resistant NSCLC. This system integrates both internal and external stimuli-responsive mechanisms that need to be activated in a preset sequence, enabling it to precisely control drug release behavior for enhancing therapeutic precision. By programming the system to respond to sequential near-infrared (NIR) irradiation and enzyme (cathepsin B) inputs, the release of gefitinib is effectively confined to the tumor region. Moreover, the NIR irradiation induces reactive oxygen species production, suppressing tumor growth and inhibiting bypass signaling pathways. The designed drug delivery system offers a highly controlled and targeted therapeutic approach, effectively inhibiting tumor growth, suppressing bypass signaling pathways, and overcoming EGFR-TKI resistance, thus offering a potential solution for maximizing therapeutic benefits.

Rational analysis of hydrogen bonding interaction in phenazine, 2-hydroxynaphthalene (1:1) cocrystal: from molecular modeling to photophysical properties

CONTEXT

Organic cocrystals have a wide range of applications in the field of optics due to their photo responsive property. We present here a newly synthesized phenazine 2-hydroxynaphthalene (1:1) cocrystal, its structural and theoretical calculations which tend to the nonlinear optical property. In the crystal structure of the title cocrystal, the phenazine and 2-hydroxynaphthalene molecules from one- and two-dimensional supramolecular frameworks via O‒H…N hydrogen bonds and C‒H…N, C‒H…π interaction, respectively. The phenazine molecules from an infinite off-set stacking through π…π interaction in the three-dimensional molecular packing of the title cocrystal. The contribution of intermolecular interaction in the three-dimensional molecular packing and the interaction energy calculation is studied by the Hirshfeld surface analysis. The molecular geometry retrieved from the experimental X-ray diffraction analysis is in good agreement with the theoretically calculated parameters. Further, the molecular electrostatic potential (MEP) and frontier molecular orbital (FMO) analysis have been carried out to study the charge distribution and molecular reactive mechanism. Third-order nonlinear optical property of the cocrystals has been analyzed by Z-scan measurements. The determined nonlinear optical absorption coefficient value 6.442 × 10-05 (m/W) and the nonlinear refractive index value - 5.535 × 10-2 (m/W) suggest that the crystalline solid can be a good choice of potential nonlinear optical material.

METHOD

The crystal structures of phenazine 2-hydroxynaphthalene cocrystal was solved by direct methods procedure using SHELXS program and refined by full-matrix least square procedure on F2 using SHELXL-2018 program on Olex2 software. The computational calculation has been carried out using DFT/B3LYP quantum chemical function with triple zeta 6-311 +  + basis set in the ground state molecular stability using Gaussian 09W program suite. The Hirshfeld surface analysis mapping, associated 2D fingerprint plot, and intermolecular molecular interaction energy calculations were carried out using CrystalExplorer (version 21.5) software.

Mix and Match Tuning of the Conformational and Multistate Redox Switching Properties of an Overcrowded Alkene

Overcrowded alkenes have received considerable attention as versatile structural motifs in a range of optical switches and light-driven unidirectional motors. In contrast, their actuation by electrochemical stimuli remains underexplored, even though this alternative energy input may be preferred in various applications and enables additional control over molecular switching states and properties. While symmetric bistricyclic overcrowded enes (BAEs) containing two identical halves based on either thioxanthene (TX) or acridine (Acr) motifs are known to be reversible conformational redox switches, their redox potentials are generally too high or low, respectively, thereby preventing wider applications. Herein, we demonstrate that the "mixed" TX-Acr switch possesses redox properties that lie between those of its parent symmetric analogs, enabling interconversion between three stable redox and conformational states at mild potentials. This includes the neutral anti-folded, the dicationic orthogonal, and a unique twisted monoradical cation state, the latter of which is only accessible in the case of the mixed TX-Acr switch and in a pathway-dependent manner. Consequently, with this multistate redox switch, a myriad of molecular properties, including geometry, polarity, absorbance, and fluorescence, can be modulated with high fidelity and reversibility between three distinct stable states. More generally, this study highlights the versatility of the "mix and match" approach in rationally designing redox switches with specific (redox) properties, which in turn is expected to enable a myriad of applications ranging from molecular logic and memory to actuators and energy storage systems.

Use of Molecular Logic Gates for the Tuning of Chemosensor Dynamic Range

Dynamic range is a crucial aspect in the development of fluorescent chemosensors. We aimed to address this issue using molecular logic gates. By creating an AND logic gate with two binding sites for the same type of ion, we increased the dynamic range of a sodium chemosensor while still using the same ionophore. Naphthalimide derivatives 1 and 2 were synthesized to test the plausibility of this application. Being an AND logic gate, the second molecule requires two Na+ ions, while molecule 1 requires a single ion for sensing. The application of this molecular logic gate is a useful method of altering the chemosensor range.

Buckybowl Molecular Tweezers for Recognition of Fullerenes

Buckybowl tweezers are a relatively young research area closely associated with the development of non-planar polycyclic aromatic systems and supramolecular chemistry. Since the appearance of the first prototypes in the early 2000s, the tweezers have undergone evolutionary changes. Nowadays they are able to effectively interact with fullerenes and the results opened up prospects for development in the field of sensing, nonlinear optics, and molecular switchers. In the present study, examples of corannulene-based and other buckybowl tweezers for the recognition of C60 and C70 fullerenes were summarized and analyzed. The main structural components of the tweezers were also reviewed in detail and their role in the formation of complexes with fullerenes was evaluated. The revealed structural patterns should trigger the development of novel recognition systems and materials with a wide range of applications.

Design and engineering of logic genetic-enzymatic gates based on the activity of the human CYP2C9 enzyme in permeabilized Saccharomyces cerevisiae cells

Gene circuits allow cells to carry out complex functions such as the precise regulation of biological metabolic processes. In this study, we combined, in the yeast S. cerevisiae, genetic regulatory elements with the enzymatic reactions of the human CYP2C9 and its redox partner CPR on luciferin substrates and diclofenac. S. cerevisiae cells were permeabilized and used as enzyme bags in order to host these metabolic reactions. We engineered three different (genetic)-enzymatic basic Boolean gates (YES, NOT, and N-IMPLY). In the YES and N-IMPLY gates, human CYP2C9 was expressed under the galactose-inducible GAL1 promoter. The carbon monoxide releasing molecule CORM-401 was used as an input in the NOT and N-IMPLY gates to impair CYP2C9 activity through inhibition of the Fe+2- heme prosthetic group in the active site of the human enzyme. Our study provides a new approach in designing synthetic bio-circuits and optimizing experimental conditions to favor the heterologous expression of human drug metabolic enzymes over their endogenous counterparts. This new approach will help study precise metabolic attributes of human P450s.

Multidimensional Dynamic Control of Supramolecular Phthalocyanine Gear: A Self-Assembly System Responding to Solvent, Temperature, and Hydrostatic Pressure

Smart supramolecular materials that respond toward various external stimuli hold great promise for various applications in molecular memories, logic gates, and drug delivery systems. In this study, the active control over the self-assembly of phathalocyanine gear was achieved by combining temperature and hydrostatic pressure stimuli with a dynamic solvent. Eventually, we found that the supramolecular gear can behave as a logic gate; "engaged" (+1) or "not" (0) state is switchable by solvent, temperature, and hydrostatic pressure. This paper describes not only new aspects for the rational design of smart stimuli-responsive supramolecular materials but also the significance of multidimensional dynamic control.

Using non-adiabatic excitation transfer for signal transmission between molecular logic gates

Molecular logic gates (MLGs) are molecules which perform logic operations. They can potentially be used as building blocks for nano-sized computational devices. However, their physical and functional integration is a difficult task which remains to be solved. The problem lies in the field of signal exchange between the gates within the system. We propose using non-adiabatic excitation transfer between the gates to address this problem while absorption and fluorescence are left to communicate with external devices. Excitation transfer was studied using the modified Bixon-Jortner-Plotnikov theory with the example of the 3H-thioxanthene-TTF-dibenzo-BODIPY covalently linked triad. Several designs of the molecule were studied in a vacuum and cyclohexane. It was found that the molecular logic system has to be planar and rigid to isolate radiative interfaces from other gates. Functioning of these gates is based on dark πσ*-states in contrast to bright ππ*-states of radiative interfaces. There are no fundamental differences between ππ* → πσ* and ππ* → ππ* transitions for cases when an exciton hops from one gate to another. The rates of such transitions depend only on an energy gap between states and the distance between gates. The circuit is highly sensitive to the choice of solvent which could rearrange its state structure thereby altering its behavior. According to the obtained results, non-adiabatic transfer can be considered as one of the possible ways for transmitting a signal between MLGs.

Nitroxyl donating and visualization with a coumarin-based fluorescence probe

Nitroxyl (HNO), the single-electron reduction product of nitric oxide (NO), has attracted great interest in the treatment of congestive heart failure in clinical trials. In this paper, we describe the first coumarin-based compound N-hydroxy-2-oxo-2H-chromene-6-sulfonamide (CD1) as a dualfunctional HNO donor, which can release both an HNO signaling molecule and a fluorescent reporter. Under physiological conditions (pH 7.4 and 37 °C), the CD1 HNO donor can readily decompose with a half-life of ∼90 min. The corresponding stoichiometry HNO from the CD1 donor was confirmed using both Vitamin B12 and phosphine compound traps. In addition to HNO releasing, specifically, the degradation product 2-oxo-2H-chromene-6-sulfinate (CS1) was generated as a fluorescent marker during the decomposition. Therefore, the HNO amount released in situ can be accurately monitored through fluorescence generation. As compared to the CD1 donor, the fluorescence intensity increased by about 4.9-fold. The concentration limit of detection of HNO releasing was determined to be ∼0.13 μM according to the fluorescence generation of CS1 at physiological conditions. Moreover, the bioimaging of the CD1 donor was demonstrated in the cell culture of HeLa cells, where the intracellular fluorescence signals were observed, inferring the site of HNO release. Finally, we anticipate that this novel coumarin-based CD1 donor opens a new platform for exploring the biology of HNO.

Engineering colloidal semiconductor nanocrystals for quantum information processing

Quantum information processing-which relies on spin defects or single-photon emission-has shown quantum advantage in proof-of-principle experiments including microscopic imaging of electromagnetic fields, strain and temperature in applications ranging from battery research to neuroscience. However, critical gaps remain on the path to wider applications, including a need for improved functionalization, deterministic placement, size homogeneity and greater programmability of multifunctional properties. Colloidal semiconductor nanocrystals can close these gaps in numerous application areas, following years of rapid advances in synthesis and functionalization. In this Review, we specifically focus on three key topics: optical interfaces to long-lived spin states, deterministic placement and delivery for sensing beyond the standard quantum limit, and extensions to multifunctional colloidal quantum circuits.

Designing Unconventional Molecular Ternary INHIBIT Logic Gate and Crafting Multifunctional Molecular Logic Systems

The paper describes an improved method for building flexible interswitchable logic gates such as rare-type molecular ternary INHIBIT and combinational logic circuits using a specially designed pyridine-end oligo-p-phenylenevinylene compound featuring alkyl substituents (-C16H33) in a THF medium. The probe molecule showed distinct opto-chemical signals upon interaction with Cu(II) and Hg(II) in THF medium. It is interesting to note that the presence of certain anions (S2-, I-, and CN-) could specifically mask the interaction of either of these metal ions or both. The most exciting thing is that we used a completely new gate design technique to construct a rare-type ternary INHIBIT logic gate using Cu(II), Hg(II), and CN- ions as three chemical inputs. With the identical set of chemical inputs, two more ternary combinational logic circuits were created out of these case-specific, independent reversible and irreversible spectroscopic studies. Finally, we were able to design adaptive molecular logic systems composed of several logic gates, including NOR, AND, IMPLICATION, INHIBIT, TRANSFER, and COMPLEMENT, that in this specific situation change the sort of logic sense by effortless optical toggling.

19F NMR Probes: Molecular Logic Material Implications for the Anion Discrimination and Chemodosimetric Approach for Selective Detection of H2O2

Detection and discrimination of similar solvation energies of bioanalytes are vital in medical and practical applications. Currently, various advanced techniques are equipped to recognize these crucial bioanalytes. Each strategy has its own benefits and limitations. One-dimensional response, lack of discrimination power for anions, and reactive oxygen species (ROS) generally limit the utilized fluorescent probe. Therefore, a cutting-edge, refined method is expected to conquer these limitations. The use of 19F NMR spectroscopy for detecting and discriminating essential analytes in practical applications is an emerging technique. As an alternative strategy, we report two fluorinated boronic acid-appended pyridinium salts 5-F-o-BBBpy (1) and 5-CF3-o-BBBpy (2). Probe (1) acts as a chemosensor for identifying and discriminating inorganic anions with similar solvation energies with strong bidirectional 19F shifts in the lower ppm range. Probe (2) turns as a chemo dosimeter for the selective detection and precise quantification of hydrogen peroxide (H2O2) among other competing ROS. To demonstrate real-life applicability, we successfully quantified H2O2 via probe (2) in different pharmaceutical, dental, and cosmetic samples. We found that tuning the -F/-CF3 moiety to the arene boronic acid enables the π-conjugation, a crucial prerequisite for the discrimination of anions and H2O2. Characteristic 19F NMR fingerprints in the presence of anions revealed a complementary implication (IMP)/not implication (NIMP) logic function. Finally, the 16 distinct binary Boolean operations on two logic values are defined for "functional completeness" using the special property of the IMP gate. Boolean logic's ability to handle information by utilizing characteristic 19F NMR fingerprints has not been seen previously in a single chemical platform for detecting and differentiating such anions.

Computation Implemented by the Interaction of Chemical Reaction, Clustering, and De-Clustering of Molecules

A chemical reaction and its reaction environment are intrinsically linked, especially within the confines of narrow cellular spaces. Traditional models of chemical reactions often use differential equations with concentration as the primary variable, neglecting the density heterogeneity in the solution and the interaction between the reaction and its environment. We model the interaction between a chemical reaction and its environment within a geometrically confined space, such as inside a cell, by representing the environment through the size of molecular clusters. In the absence of fluctuations, the interplay between cluster size changes and the activation and inactivation of molecules induces oscillations. However, in unstable environments, the system reaches a fluctuating steady state. When an enzyme is introduced to this steady state, oscillations akin to action potential spike trains emerge. We examine the behavior of these spike trains and demonstrate that they can be used to implement logic gates. We discuss the oscillations and computations that arise from the interaction between a chemical reaction and its environment, exploring their potential for contributing to chemical intelligence.

Enhancing Control Over Nitric Oxide Photorelease via a Molecular Keypad Lock

Based on Boolean logic, molecular keypad locks secure molecular information, typically with an optical output. Here we investigate a rare example of a molecular keypad lock with a chemical output. To this end, the light-activated release of biologically important nitric oxide from a ruthenium complex is studied, using proton concentration and photon flux as inputs. In a pH-dependent equilibrium, a nitritoruthenium(II) complex is turned into a nitrosylruthenium(II) complex, which releases nitric oxide under irradiation with visible light. The precise prediction of the output nitric oxide concentration as function of the pH and photon flux is achieved with an artificial intelligence approach, namely the adaptive neuro-fuzzy inference system. In this manner an exceptionally high level of control over the output concentration is obtained. Moreover, the provided concept to lock a chemical output as well as the output prediction may be applied to other (photo)release schemes.

A laser-Engraved Wearable Electrochemical Sensing Patch for Heat Stress Precise Individual Management of Horse

In point-of-care diagnostics, the continuous monitoring of sweat constituents provides a window into individual's physiological state. For species like horses, with abundant sweat glands, sweat composition can serve as an early health indicator. Considering the salience of such metrics in the domain of high-value animal breeding, a sophisticated wearable sensor patch tailored is introduced for the dynamic assessment of equine sweat, offering insights into pH, potassium ion (K+), and temperature profiles during episodes of heat stress and under normal physiological conditions. The device integrates a laser-engraved graphene (LEG) sensing electrode array, a non-invasive iontophoretic module for stimulated sweat secretion, an adaptable signal processing unit, and an embedded wireless communication framework. Profiting from an admirable Truth Table capable of logical evaluation, the integrated system enabled the early and timely assessment for heat stress, with high accuracy, stability, and reproducibility. The sensor patch has been calibrated to align with the unique dermal and physiological contours of equine anatomy, thereby augmenting its applicability in practical settings. This real-time analysis tool for equine perspiration stands to revolutionize personalized health management approaches for high-value animals, marking a significant stride in the integration of smart technologies within the agricultural sector.

Fluorescent Probes for Disease Diagnosis

The identification and detection of disease-related biomarkers is essential for early clinical diagnosis, evaluating disease progression, and for the development of therapeutics. Possessing the advantages of high sensitivity and selectivity, fluorescent probes have become effective tools for monitoring disease-related active molecules at the cellular level and in vivo. In this review, we describe current fluorescent probes designed for the detection and quantification of key bioactive molecules associated with common diseases, such as organ damage, inflammation, cancers, cardiovascular diseases, and brain disorders. We emphasize the strategies behind the design of fluorescent probes capable of disease biomarker detection and diagnosis and cover some aspects of combined diagnostic/therapeutic strategies based on regulating disease-related molecules. This review concludes with a discussion of the challenges and outlook for fluorescent probes, highlighting future avenues of research that should enable these probes to achieve accurate detection and identification of disease-related biomarkers for biomedical research and clinical applications.

DNA Molecular Computation Using the CRISPR-Mediated Reaction and Surface Growth of Gold Nanoparticles

DNA has emerged as a promising tool to build logic gates for biocomputing. However, prevailing methodologies predominantly rely on hybridization reactions or structural alterations to construct DNA logic gates, which are limited in simplicity and diversity. Herein, we developed simple and smart DNA-based logic gates for biocomputing through the DNA-mediated growth of gold nanomaterials without precise structure design and probe modification. Capitalizing on their excellent plasmonic properties, the surface growth of gold nanomaterials enables distinct wavelength shifts and unique shapes, which are modulated by the composition, length, and concentration of the DNA sequences. Combined with a CRISPR-mediated reaction, we constructed DNA circuits to achieve complicated biocomputing to modulate the surface growth of gold nanomaterials. By implementing logic functions controlled by input-mediated growth of gold nanomaterials, we established YES/NOT, AND/NAND, OR/NOR, XOR, and INHIBIT gates and further constructed cascade logic circuits, parity checker for natural numbers, and gray code encoder, which are promising for DNA biocomputing.

Molecular Ratchets and Kinetic Asymmetry: Giving Chemistry Direction

Over the last two decades ratchet mechanisms have transformed the understanding and design of stochastic molecular systems-biological, chemical and physical-in a move away from the mechanical macroscopic analogies that dominated thinking regarding molecular dynamics in the 1990s and early 2000s (e.g. pistons, springs, etc), to the more scale-relevant concepts that underpin out-of-equilibrium research in the molecular sciences today. Ratcheting has established molecular nanotechnology as a research frontier for energy transduction and metabolism, and has enabled the reverse engineering of biomolecular machinery, delivering insights into how molecules 'walk' and track-based synthesisers operate, how the acceleration of chemical reactions enables energy to be transduced by catalysts (both motor proteins and synthetic catalysts), and how dynamic systems can be driven away from equilibrium through catalysis. The recognition of molecular ratchet mechanisms in biology, and their invention in synthetic systems, is proving significant in areas as diverse as supramolecular chemistry, systems chemistry, dynamic covalent chemistry, DNA nanotechnology, polymer and materials science, molecular biology, heterogeneous catalysis, endergonic synthesis, the origin of life, and many other branches of chemical science. Put simply, ratchet mechanisms give chemistry direction. Kinetic asymmetry, the key feature of ratcheting, is the dynamic counterpart of structural asymmetry (i.e. chirality). Given the ubiquity of ratchet mechanisms in endergonic chemical processes in biology, and their significance for behaviour and function from systems to synthesis, it is surely just as fundamentally important. This Review charts the recognition, invention and development of molecular ratchets, focussing particularly on the role for which they were originally envisaged in chemistry, as design elements for molecular machinery. Different kinetically asymmetric systems are compared, and the consequences of their dynamic behaviour discussed. These archetypal examples demonstrate how chemical systems can be driven inexorably away from equilibrium, rather than relax towards it.

Robust Red-Absorbing Donor-Acceptor Stenhouse Adduct Photoswitches

Donor-Acceptor Stenhouse Adduct (DASA), a class of push-pull negative photochrome, has received large interest lately owing to its versatile synthesis, modularity and excellent photoswitching in solutions. From a technological perspective, it is imperative for this class of photoswitches to work robustly in solid state, e. g. thin films. We feature a molecular framework for the optimized design of DASAs by introducing a new thioindoline donor (D3) and assessing its performance against known 2nd generation indoline-based donors. The systematic structure-function investigations suggest that to achieve robust reversible photoswitching, a ground state with low charge separation is desired. DASAs with stronger electron donors and a larger charge separation in the ground state result in a low population of the photothermalstationary state (PTSS) and reduced photostability. The DASA with thioindoline donor (D3A3) seems to be a special case among the donor series as it causes a red shift (ca. 15 nm), however with less polarization of the ground state and marginally better photostability as compared to the unsubstituted 2-methyl indoline (D1A3). We also emphasize the consideration of the key additional factors that can modulate the red-light photoswitching properties of DASA chromophores in polymer thin films, which might not be dominant in homogenous solution state.